1. Field of the Invention
The present invention relates to a computer program product, system, and method for asynchronous pausing of the formation of consistency groups
2. Description of the Related Art
In a storage environment, production volumes at a primary storage site may be copied to volumes in a secondary storage site to provide redundant copies of data. In the International Business Machine Corporation's (“IBM”) Global Mirror, data is asynchronously copied from the primary storage site to the secondary storage site. Data may be copied in consistency groups, such that copied data is consistent as of a point-in-time to a first copy of the data at the secondary site. In a consistency group, the order of dependent writes is preserved in the copying of the data.
The target data, or first copy, at the secondary site, to which the source data at the primary storage site is copied, may be copied to a second copy of the data at the secondary site using a point-in-time (“PiT”) copy techniques, such as the IBM FlashCopy® (FlashCopy is a registered trademark of IBM) In this way the target data (first copy) in the copy relationship with the source data at the primary site becomes the source data for the PiT copy to the second copy. In other implementations, such as IBM Global Copy, the second copy may be in a third site.
Customers that want to create additional copies of the target data at the secondary site, may perform a fast reverse restore operation, where replication from the primary to the secondary site is suspended and a reverse FlashCopy is made from the second copy back to the first copy, wiping out any newer data received at the first copy since the point-in-time of the second copy. After the reverse FlashCopy is made back to the first data copy, the customer may then make additional copies from the reversed first data copy.